Flexible intermediate bulk containers, also known as FIBCs, are increasingly used in the packaging and shipping of semi-bulk quantities of fine powdery food, chemical products and other powdered materials. Examples of the products that are shipped in such containers include melamine, silicon and flour. The flexible intermediate bulk container has a flexible side wall, normally in the form of a tube, with end walls having spouts thereon, one spout being for filling the container and the other spout being for discharge of the contents from the container.
Flexible intermediate bulk containers are typically filled using a gravity fill process in which the material is fed through the filling spout into the container, until such time as the container has been filled. The filling process is time consuming and may also impose hazards of an environmental and particularly an occupational health and safety nature. Dust tends to be generated in, in particular, the filling procedure and, depending on the particular product being packaged, the resultant dust cloud could be unacceptable for one or both of environmental and occupation health and safety reasons.
The typical filling process has a series of start-stop filling steps that are incorporated into the process in an attempt to ensure that the maximum capacity of the container is achieved. For instance, the flexible intermediate bulk container is filled with air so that it will maintain its proper form during the filling process. The FIBC is then placed under the dispensing spout of a hopper containing the powdered material to be packaged, with the dispensing spout of the hopper being inserted in the fill spout of the FIBC. The powdered material is slowly fed into the FIBC in an intermittent manner, to allow the flexible intermediate bulk container to de-aerate as it fills. However, this de-aeration tends to produce the dust cloud. De-aeration may be accomplished, for instance, by permitting the powdered material to settle in the FIBC and/or by application of force to the flexible part of the FIBC to urge accumulated air out of the partially-filled container. Both techniques of de-aeration are very time consuming, with the consequence that the filling of a single flexible intermediate bulk container can take as long as about 35 minutes, especially with fine powdered material.
Notwithstanding the time taken in an attempt to de-aerate the FIBC during the filling procedure, the filled flexible intermediate bulk container normally has some trapped air within the container. Thus, the FIBC is not readily stackable for transportation and there is a need to take steps to prevent a stack of the containers from shifting during transportation.
In addition to the problems in filling and transportation of FIBCs, there are problems associated with discharging the contents of the FIBC. For instance, the powdered material in the FIBC does not readily flow from the container and powdered material may pack into the corners of the FIBC and require some assistance in order to fully discharge the contents of the flexible intermediate bulk container.
Improvements in flexible intermediate bulk containers, and in both the methods of filling and discharging of such containers, are required in order to expedite the filling and discharge of the material within the container, the ability to transport filled FIBCs and to improve the environmental and especially the occupation health and safety aspects of the filling and discharging of the containers.